Upconversion Nanoparticles for Biomedical Applications provides a comprehensive overview of the chemistry, properties, characterization and emerging applications of lanthanide-doped upconversion nanoparticles (UCNPs), focusing on upconversion mechanisms, fluorescent properties, and biomedical applications. The emerging applications of UCNPs include cancer diagnostics and therapy, biosensing and bioassays, bioimaging, drug and gene delivery, cellular optogenetics, and the detection of small biomolecules and ions. The biocompatibility, biodegradability, bio-distribution, toxicity and regulatory considerations of upconversion are fully considered. This book offers a unique reference resource for researchers, bringing together a global authorship to cover the fundamentals, state of the art, current challenges and future perspectives of upconversion nanoparticles.